1. Field of the Invention
The present invention relates to a thermal transfer recording method for transferring the ink contained on an ink sheet onto a recording medium thereby recording an image thereon, and an apparatus adapted for effecting said method.
The above-mentioned thermal transfer recording apparatus includes a facsimile apparatus, an electronic typewriter, a copying machine, a printer or like.
2. Related Background Art
In general, the image recording in a thermal transfer printer is achieved by utilizing an ink sheet formed by coating a base film with a heat-fusible (or heat-sublimable) ink, selectively heating said ink sheet corresponding to image signal with a thermal head and transferring thus fused (or sublimed) ink onto a recording sheet. Said ink sheet is usually a so-called one-time ink sheet which completely loses the ink after an image recording, so that it is necessary, after the recording of a character or a line, to advance the ink sheet by amount corresponding to said recording, in order to securely bring the unused portion of the ink sheet to the next recording position. This fact increases the amount of use of the ink sheet, so that the running cost of a thermal transfer printer tends to be higher than that of the ordinary thermal printer in which the recording is made on thermal recording paper.
In order to solve such drawbacks a thermal transfer printer in which the recording sheet and the ink sheet are advanced with different speeds is proposed for example in the U.S. Pat. No. 4,456,392, the Japanese Laid-open Patent Sho 58-201686 and the Japanese Patent Publication Sho 62-58917. Also as described in said patent references, there is already known so-called multi print sheet, which is an ink sheet capable of plural image recordings, and, in continuous recording of a length L, such a multi print sheet allows users to reduce the amount of advancement of the ink sheet, during or after the image recording, to less than said length L (L/n: n&gt;1). Such method improves the efficiency of use of the ink sheet to n times, so that a reduction in the running cost of the thermal transfer printer can be expected. This method is hereinafter called the multi-printing method.
In a thermal transfer printer for such multi-printing method, the ink sheet may generate creases or slack due to the friction between the ink sheet and the recording sheet, since the moving speed of the ink sheet is smaller than that of the recording sheet. Also in such printer, there is usually provided a cutter for cutting the recorded sheet into respective pages, and the presence of such cutter is preferable in a facsimile apparatus. However, the creases or slack in the ink sheet tends to appear more strongly in the presence of said cutter, because it is necessary to feed the recording sheet toward the cutter (so-called front feeding) after the recording of a page, and to reverse the recording sheet after the cutting operation of the cutter, until the leading end of the sheet comes close to the recording position with the thermal head (so-called back feeding).